Murfreesboro is a city in Pike County, Arkansas, United States. The population was 1,764 at the 2000 census. The city is the county seat of Pike County. Crater of Diamonds State Park is located just to the south. The crater is an eroded lamproite pipe where diamonds were discovered in 1906. 100,000 were found by 1933, and visitors to the park may still take away whatever they can find.
The guard cells surround each stoma in a plant cell. They regulate  the opening and closing of stomata to facilitate gas exchange and  control transpiration in plants.
These bubbles can block water transport and cause water deficit in leaves. Plants avoid cavitation or minimize its damage through several mechanisms: 1) Xylem cells possess pits or tiny holes that allow liquid water transport, but do not allow the gas bubble to escape; this structural characteristic helps keep the gas bubble in one cell, so the other xylem cells can continue to transport water up the plant. 2) Water will detour around any xylem cell containing an air bubble through the pits as well.